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Wednesday, April 1, 2015

A Mystery Orchid

This stopped me in my tracks. Flowering for the first time near the top a tree in the Tropical High Elevation House was an orchid I'd not noticed before. With its big solitary flower, it looked almost like an adolescent Pleurothallis gargantua. But the feeling that something was amiss sent me scurrying to the back up greenhouse for a ladder and then a closer look.

The handwritten label from Ecuagenera Nursery read 'Pleurothallis teaugei + gargantua.'  Odd. What did the plus sign mean? If Ecuagenera had created a hybrid, wouldn't they have labeled it with the names of the parents, separated by an 'x'? Is this plant a hybrid? Are teaguei and gargantua the parents?

Here's Pleurothallis gargantua, with its enormous solitary flower. For a quick guide to the floral parts, go here. The sepals look very much like those of our unknown orchid. But note that gargantua's rosy petals and yellow lip are very different.

And here's Pleurothallis teaguei flowering in the Tropical High Elevation House. If our unknown orchid is a hybrid, it could have inherited the rolled white petals from a teaguei. But where is it getting its rosy lip? Most likely not from gargantua or teaguei.

Flowering simultaneously was Pleurothallis marthae. With its rolled white petals and rosy lip, it appears to be a more likely contributor to the unknown orchid's genome.

But I can't be sure. The first step toward putting a name on this plant is to email a picture to Ecuagenera Nursery and ask for their data. Pleurothallid hybridization isn't exactly trending among commercial orchid growers, but I wouldn't be shocked if it were a hybrid. The larger Pleurothallids are fairly easy to pollinate. Alternatively, could this be a plant that Ecuagenera collected not in flower, and perhaps the names on the label were meant to be speculative? Could it be a species? There is nothing like it in Icones Pleurothallidinarum.

Whatever it is, our mystery Pleurothallis is a handsome plant. You can see it flowering now on the tree next to the door to the Conservation greenhouse.

Saturday, March 28, 2015

The Frogs

The frogs are flowering. The 'frogs' are a group of related orchid species within the vast subtribe Pleurothallidinae. (Acronia section Macrophyllae-Fasciculatae or Pleurothallis subsections Acroniae and Macrophyllae-Fasciculatae, depending on who you ask). The hooded sepals and spongy lip give the flowers the whimsical appearance of open-mouthed frogs. They are awesome.
What's inside those gaping mouths? Frog flowers can be baffling if you approach them with the expectation of seeing the conventional 3 + 3 arrangement of orchid petals and sepals. Here is a close up guide to a couple of the larger species, Pleurothallis gargantua and Pleurothallis marthae.

The dorsal sepal is usually erect and often concave. The lateral sepals are fused to form a synsepal. Lying opposite each other like the two halves of a clamshell, the dorsal sepal and synsepal give the flowers their mouth-like appearance. Pleurothallis gargantua (above) is a spectacular example and the largest of the frog Pleurothallids.

Pleurothallis marthae produces flowers that seem to remain half open. In the photo above, I've pulled back the dorsal sepal so you can see the interior of the flower from above. The column is short and the stigmatic surface is at its apex, not on the underside. The tiny anther has a detachable anther cap covering a minute pair of teardrop shaped pollinia.

Above, I've cut away part of the leaf of Pleurothallis marthae so you can get a closer look at the inflorescence. The inflorescence emerges near the apex of the ramicaul, a secondary stem that looks very much like a petiole. (The actual petiole is quite short and is separated from the ramicaul by an abscission layer.) The inflorescence is subtended by a sheath, called a spathe, that mostly obscures the peduncles. From the peduncles the solitary pedicels arise, each surrounded by a clear tubular bract, and emerge from the spathe. Among frog Pleurothallids, flowers are produced singly and one at a time (as in Pleurothallis gargantua), or singly and simultaneously (as in P. marthae).

The 'frogs' in the Tropical  High Elevation House are putting on an amazing show right now. Don't miss these terrific orchids!

Saturday, March 7, 2015

Openings: Acineta cryptodonta

Here it is -the high point of my week- the long awaited opening of Acineta cryptodonta. And what a payoff. The first flowering of any unusual orchid generates some buzz among our greenhouse staff, but this plant is something special.

Maybe it's the color -the luminous pastel yellow of the flowers that keep me circling back for another look. Or the weird, almost bitter mixture of fragrances, unlike any other Euglossine-pollinated orchid that I have encountered. Is there a hint of indole in that fragrance? And the name 'cryptodonta' makes me want to open up a flower to find the hidden tooth.

It's not easy to find information about this species. Gunter Gerlach's Stanhopeinae site has some fascinating shots of the plant cloaked in moss on steep slopes in Venezuela at 1400 m. accompanied by bromeliads, aroids and gesneriads. Apparently it is also known from Colombia.

You can find our plant growing in a cedar basket in the Tropical High Elevation House growing in a mixture of moss and tree fern fiber. Be sure to look for it in the back of the greenhouse. There is a second spike forming, so if you miss it this week, check back in about three weeks.

Sunday, March 1, 2015

Dendrobium obtusiwhat?

Full disclosure: I'm not 100% certain of the name of this plant. But I'm fairly certain it is not Dendrobium obtusisepalum, the name that appeared on the label that we received from the grower.

Dendrobium obtusisepalum is a name that appears in the horticultural trade, but is not recognized as a legitimate name for any Dendrobium species. There exists a Dendrobium obtusipetalum, a synonym for Dendrobium wentianum, but that is not our plant. I believe our plant may be Dendrobium chrysopterum Schuit. & de Vogel. But I won't know until an inter-library loan delivers the original description published in the journal Orchideenfreund.

Why does it matter? In addition to maintaining the accuracy of our plant records, the correct name determines how we grow our plants. Dendrobium obtusipetalum is a high elevation species. But Dendrobium chrysopterum grows at 600 to 800 meters, with year round intermediate to warm temperatures and copious rainfall. If we want to keep this plant alive, we need to know its correct name.

Dendrobium chrysopterum grows in the Lake Kutubu area in the Southern Highlands Province of Papua New Guinea, according to Lavarack, Harris and Stocker in Dendrobium and its Relatives. It grows as an epiphyte in trees on lowland forest ridges where daytime maximum temperature reaches 87º F.

Regardless of name, this plant is a stunner and it could be the most commented upon orchid we have on display this week. The candy corn colored flowers are grouped on arching leafless pseudobulbs. The new pseudobulbs have purple tinged leaves. I'm hoping we can set a capsule on this plant this week.

Sunday, February 22, 2015

The Orchids of Orchid Daze

Dendrobium Wave King 'Sazanami'
Here's your cheat sheet, a photo ID guide to many of the orchids in this year's Orchid Daze display. I'll follow up with a how-to-grow guide right before our very popular Gently Used Plant Sale, April 15-17. Mark your calendar!
Odontocidium Wildcat 'Silver'
Phalaenopsis OX Lottery
Dendrobium Roy Tokanaga
Phalaenopsis Kaleidoscope
Dendrobium Red Emperor 'Prince'
Phalaenopsis Golden Apple
Odontocidium Catante 'Pacific Sun Spots'
Odontocidium Wildcat 'Bobcat'
Odontocidium Wildcat 'Green Valley'
Phalaenopsis OX Lottery
Paphiopedilum and Cattleya hybrids

Friday, February 20, 2015

Behind the Scenes: Orchid Daze 2015

This year's Orchid Daze installation flew past like an express train. Orchid Daze: Pop!, our Pop Art-inspired orchid display is now open! Here's a look at our work in progress and eight fun facts about this year's display.

1. Best Orchid Daze Selfie Opportunity: the Conservatory Lobby. Take your picture alongside a 60's pop icon.

2. The planters in our Warhol orchid gallery are actual soup cans. 
For our Warhol-inspired orchid display in the Conservatory Lobby, I was enlisted to investigate soup can options. The assignment: find a can approximating Campbell's soup proportions that is large enough to hold an orchid. In the interest of Orchid Daze research I consumed in one weekend one 46 oz can of Beef-a-roni, a can of ravioli, and a truly disgusting lunch of SpaghettiOs before settling on the Swanson's Chicken Broth as the ideal can.

3. The labels are original. Our graphics designer Chris Kozarich created the witty orchid graphics based on the works of Andy Warhol, Keith Haring and Roy Lichtenstein, including those brilliant soup can labels.

4. Most popular plant combo: Phalaenopsis OX Lottery and yellow Kalanchoe.

4. Most controversial item: the ironic use of urban chic trash cans overflowing with orchids in the Keith Haring-inspired display in the Orchid Atrium.

5. Runner up: the fire hydrants in electric colors.

6. Pro's Secret: The orchids that appear to be planted in beds are actually sunk in the mulch still in their pots.

7. Most popular graphic: 'Hello Gorgeous!', the Cattleya orchid admiring itself in a mirror. Look for it in the Roy Lichtentein-inspired display in the Orchid Display House.

8. Who designs our Orchid Daze displays? It's Tres Fromme, above, placing one of the Lichtenstein graphics.

Come see Orchid Daze! There is no better place on a frigid day than a warm greenhouse bursting with orchid color. Orchid Daze: Pop! runs through April 12.

Tuesday, January 27, 2015

In Memorium

Dorothy Chapman Fuqua 1921-2015
It is with tremendous sadness that I note the passing of our great friend and patron, Mrs. Dorothy Chapman Fuqua. Mrs. Fuqua was a friend to everyone at the Garden. The Atlanta Botanical Garden wouldn't be what it is today without the support of Mrs. Fuqua, her husband, J.B., and their family. I remember Dottie as an extraordinarily thoughtful and kind woman, who always made time to chat, whose concern was always for others, and who understood the healing nature of gardens. Her desire to share beauty and tranquility with the people of Atlanta gave life to our dream of a conservatory and orchid center for our community and beyond. She was a jewel. We will miss her.

Friday, January 16, 2015

Pink Tulip Orchid

At first glance, it would be possible to mistake this beautiful plant for Anguloa uniflora, another pink tulip orchid species. But Anguloa virginalis is recognizable by its laterally flattened flowers with pointed petals and sepals.

Front view, showing how narrow the flower of Avirginalis is compared with  A. uniflora. Orchid flowers have bilateral symmetry. But like virtually all organisms, this individual defies any expectation of symmetrical perfection. The column is turned slightly left of center, reflecting a twist in the ovary and scape. The two lower sepals meet unevenly. One sepal points slightly leftward. I like these fascinating  irregularities.

From the side, you can see the distinctive kink near the base of the tubular lip -a feature that is diagnostic for virginalis.

Ventral view of the lip. From this angle, you can see that the kink in the lip is actually a depression in the ventral surface.

Dorsal view of the lip.

Anguloa virginalis is native to Colombia, Ecuador and Peru, where it grows as a terrestrial or lithophyte at around 2000 meters elevation in bright light. Henry Oakeley reports its habitat as full sun or light woodland and forest margins. Our plants like the cool temperatures (52º night minimum) of our Tropical High Elevation House where they are planted in the ground in a mixture of fine fir bark, charcoal and permatill.
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